Towards Efficient Acidic Catalysts via Optimization of SO3H-Organosilane Immobilization on SBA-15 under Increased Pressure: Potential Applications in Gas and Liquid Phase Reactions.

Maciej Trejda,Maria Ziolek,Ardian Nurwita,Ada Kaszuba

doi:10.3390/ma14237226

Maciej Trejda, Maria Ziolek + Show 2 more

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https://doi.org/10.3390/ma14237226

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Journal: Materials	Publication Date: Nov 26, 2021
Citations: 1	License type: CC BY 4.0

Affiliation: Adam Mickiewicz University in Poznań

Abstract

In this paper, the optimization of the synthesis of catalysts based on acidic mesoporous silica of the SBA-15 type by post-synthesis immobilization of 3-(trihydroxysilyl)-1-propanesulfonic acid (TPS) under increased pressure up to 20 bar is reported. Sample structures and composition were examined by XRD measurement, low-temperature N2 adsorption/desorption and elemental analysis. The catalytic activities of the materials obtained were determined in both gas and liquid phase processes, i.e., by esterification of acetic acid and glycerol dehydration, respectively. The optimum pressure for modification leading to the highest number of acidic sites was found to be 10 bar. The final material was very active and stable in liquid phase processes; however, the stability in the gas-phase process was unsatisfactory due to the loss of sulphonic species from the catalyst surface.

Highlights

Numerous chemical transformations involving acid catalysts are of great importance in industrial applications
In view of the above, the main goal of this study was to examine the impact of pressures up to 20 bar applied during post-synthesis modification of SBA-15 on the efficiency of TPS species incorporation
SBA-15 was functionalized with 3-(trihydroxysilyl)-1-propanesulfonic acid (TPS) following its synthesis at different pressures during the modification process

Summary

Introduction

Numerous chemical transformations involving acid catalysts are of great importance in industrial applications. This group includes a significant number of processes performed in the homogeneous phase, usually catalyzed by mineral acids [1]. The catalyst cannot be separated from the reaction mixture, which implies the formation of waste products as a result of the neutralization of mineral acid. This results in a greater burden on the natural environment and is against the rules of so-called green chemistry [3]. Most of the aforementioned problems can be eliminated by application of solid catalysts having acidic sites on their surface

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